Here is a specifications overview of the Tascam Portastudio 246, a 4 track cassette recorder with a 6 channel mixer which came to market in 1985.

___________________________________________________________________________________
TETRAKAN - Fix & Use Tape Recorders

Overviews; tear-downs; repair vlogs; techniques; tutorials; demo recordings...
...covering every cassette multitrack recorder ever made!*
*(eventually)
   / tetrakan  

Paypal donations are gratefully accepted via my blog, which also features written articles and free downloads of service manuals;-
https://tetrakansupermonobloc.home.blog/

If you would like to make a regular donation check out my Patreon account;-
  / tetrakan  

I prefer to answer questions in the youtube comments where my answers can help more than one person, but if you need to share photos etc, you can message me via facebook.
  / tetrakan  

Tools and equipment I use when repairing portastudios;-
https://kit.co/Tetrakan